2. Epidemiology
Onset- ~2-3 weeks after streptococcal
infection
Rate of development after untreated infection-
~3%
Recurrence with a subsequent untreated
infection- 5-50%, more in patients with RHD
Common in children- age 5-15,
only 20% first attacks in adults
3. Pathogenesis
Possible autoimmune disease
Follows pharyngitis due to encapsulated GABH streptococci
A complex interplay of genetically determined host
susceptibility, pathogenic GABH streptococcal infection,
in a susceptible environment
Best defined virulence factor- M protein
Present on surface of bacteria
Promotes bacterial adherence & resist phagocytosis
Shares homology with cardiac myosin, tropomyosin, keratin, laminin
Types 1,3,5,6,14,18,19,24 associated with ARF
Other-
T cell activation by streptococcal superantigens,
leading to granuloma formation
4. Pathology
Myocardial Aschoff body- a submiliary
granuloma, later forms scar
Endocardial verrucous valvulitis, heals
with fibrous thickening & adhesions,
causing stenosis or regurgitation
Serofibrinous pericarditis
Joint- exudative arthritis
Subcutaneous nodules- granuloma
5. Modified Jones’ criteria
Used for diagnosis
2 major or 1 major+2 minor or 2
minor (in patient with RHD), with
evidence of streptococcal infection
Evidence of s’coccal infection
within last 45 days-
Elevated/rising ASO/anti-DNase B titres
Positive throat culture
Rapid Ag test for GABH s’cocci
Recent scarlet fever
11. Treatment
Acute streptococcal infection-
1.2 million units of benzathine penicillin G
or amoxycillin/1st
gen. oral cephalosporin x 10 days
Erythromycin, 500 BD x 10 days,
if penicillin sensitive/allergic
Acute arthritis- ASA/NSAIDs
Acute carditis- prednisolone, rest, diuretics, ACEI
Chorea- diazepam, haloperidol, carbamazepine
Monitor ESR/CRP for duration of symptomatic
Rx
12. Prophylaxis
1.2 million units of benzathine penicillin G,
IM q 3-4 weeks
Sulfadiazine, 500 BD or Erythromycin, 250 BD,
if penicillin sensitive
Duration-
Without carditis- X 10 years or upto 21 years of age,
whichever is longer (WHO- x 5 yrs./upto 18 yrs. of age)
With carditis/RHD- upto 40 years of age
(WHO- X 10 yrs./upto 25 yrs. of age)
Severe RHD/after valve Sx- lifelong
Problem- compliance
No recurrence with proper compliance